JP7603540B2 - Compressed air storage power generation equipment - Google Patents

Description

The present invention relates to a compressed air storage power generation device.

A wind turbine device in which a wind turbine is installed on a floating body on the ocean is known (for example, Patent Document 1). This wind turbine device does not have a structure for storing electricity, and uses the electricity generated by the wind turbine on the ocean as it is.

JP 2005-264865 A

The amount of power generated by the above wind turbine device depends on weather conditions, so output is unstable. Therefore, it is difficult to supply power in a timely manner according to power demand.

Compressed air energy storage (CAES) power generation equipment is also known for stabilizing the output of power generation using renewable energy. In a CAES power generation equipment, a compressor is driven by electricity generated using renewable energy, and the compressed air produced by the compressor is stored in an accumulator such as a tank. The compressed air in the accumulator is then used when needed to drive a turbine generator, enabling timely power generation.

In CAES power generation equipment, the pressure accumulator may become large, and a large space must be secured to install the pressure accumulator. Securing the installation space for the pressure accumulator on the ground also incurs large costs.

The objective of the present invention is to utilize above- or underwater space in a compressed air storage power generation system.

The present invention provides a compressed air storage power generation device comprising a float that floats on water, a power generation facility that generates power using renewable energy, an electric motor driven by electricity generated by the power generation facility, a compressor that compresses air by being driven by the electric motor, a pressure storage unit that stores compressed air discharged from the compressor, an expander that expands the compressed air stored in the pressure storage unit, and a generator driven by the expander, the pressure storage unit being attached to the float and at least partially disposed underwater, and the power generation facility being disposed on a structure that floats due to the buoyancy of the float.

According to this configuration, since the pressure storage unit is at least partially disposed underwater, space above or below the water can be utilized. Similarly, since the power generation equipment that generates electricity using renewable energy is disposed in a structure that floats due to the buoyancy of the float, space above or below the water can be utilized. Here, the form of the structure that floats due to the buoyancy of the float is not particularly limited, and it may be integrated with the float (i.e., it may be the float itself) or it may be separate from the float.

The pressure accumulator may be a bottomless container.

With this configuration, water can flow in and out of the pressure accumulator from below. This automatically adjusts the volume required for the pressure accumulator, eliminating the need for a large tank as the pressure accumulator.

The pressure accumulator may be a tank that is entirely placed underwater and is fluidly connected to a pipe that is open underwater.

With this configuration, the accumulated pressure can be adjusted by appropriately setting the depth to which the tank is submerged, and good compression and expansion efficiencies can be achieved in the compressor and expander. In addition, since the tank can be submerged in water, construction is easy.

The piping may be provided with a water flow generator that generates electricity by being driven by the water flow generated by the water flowing in and out.

With this configuration, electricity is generated not only by a generator but also by a water current generator, ensuring a large amount of electricity generation.

The compressor and expander may be located inside or on top of the structure.

With this configuration, the compressor, pressure accumulator, and expander, which need to be connected by piping for flowing compressed air, are placed in the structure, so the piping can be completed near the float (structure). In other words, there is no need to extend piping from the float (structure) to the ground. The above configuration is effective because the piping for flowing compressed air is thicker than electric wires and is not easy to handle.

The compressor and the expander may be integrated into a combined compressor/expander.

This configuration allows the installation space for the compressor and expander (combined compression and expansion machine) to be reduced. This configuration is particularly effective when the compressor and expander (combined compression and expansion machine) are installed inside or on top of a floating body (structure), as the installation space is limited.

The present invention allows compressed air storage power generation equipment to utilize above-water or underwater space.

1 is a schematic configuration diagram of a compressed air storage power generation device according to a first embodiment of the present invention. FIG. FIG. 5 is a schematic diagram of a compressed air storage power generation device according to a second embodiment. FIG. 11 is a schematic diagram of a compressed air storage power generation device according to a third embodiment. FIG. 13 is a schematic diagram of a compressed air storage power generation device according to a fourth embodiment. FIG. 13 is a schematic diagram of a compressed air storage power generation device according to a fifth embodiment.

The following describes an embodiment of the present invention with reference to the attached drawings.

First Embodiment
FIG. 1 is a schematic configuration diagram of a CAES power generation device 1 according to a first embodiment of the present invention.

The compressed air energy storage (CAES) power generation system 1 utilizes space on or underwater, such as the sea or a lake. In Figure 1, the water surface is indicated by the symbol 2, the underwater area is indicated by the symbol 3, and the surface area is indicated by the symbol 4. This is the same in the following figures.

The CAES power generation device 1 has a float (structure) 10, a power generation facility 20, a motor (electric motor) 30, a compressor 40, a pressure storage unit 50, an expander 60, and a generator 70. In FIG. 1, the float 10 and the pressure storage unit 50 are shown in cross section with hatching to clarify the illustration.

The float 10 floats on water. The float 10 is designed to have a buoyancy that prevents it from sinking even when the components of the CAES power generation device 1 are installed, as described below. The float 10 is integrally configured as a structure that floats due to buoyancy, and here, there is no distinction between the float and the structure, both of which are indicated by the symbol 10, and hereafter will be referred to simply as the structure 10. However, the float and the structure may be provided as separate bodies.

The power generation facility 20 generates power using renewable energy. In this embodiment, the power generation facility 20 has a wind power generation function. Alternatively, the power generation facility 20 may have a function such as water temperature difference power generation, tidal power generation, or solar power generation.

In this embodiment, the power generation equipment 20 is disposed on top of the structure 10. Although not shown in detail, the power generation equipment 20 may be disposed on a separate structure that floats due to the buoyancy of the structure 10. The power generation equipment 20 is electrically connected to the motor 30 via wiring 5a. The electricity generated by the power generation equipment 20 is supplied to the motor 30 via wiring 5a.

The motor 30 is driven by electricity generated by the power generation equipment 20. The motor 30 is mechanically connected to the compressor 40.

The compressor 40 is driven by the motor 30. The compressor 40 draws in external air through an intake port 41, compresses it internally, and discharges the compressed air from a discharge port 42. The discharge port 42 of the compressor 40 is fluidly connected to the pressure accumulator 50 via a pipe 6a. The type of the compressor 40 is not particularly limited, but may be a screw type.

The pressure accumulator 50 stores the compressed air discharged from the compressor 40. The pressure accumulator 50 is attached to the structure 10. In this embodiment, the pressure accumulator 50 is partially disposed underwater 3. In other words, the pressure accumulator 50 is partially exposed above the water 4. In this embodiment, the pressure accumulator 50 is a bottomless container. Therefore, the inside of the pressure accumulator 50 is divided into an air layer S1 and a water layer S2. The pressure accumulator 50 is fluidly connected to the air supply port 61 of the expander 60 via the pipe 6b.

The expander 60 receives compressed air from an air inlet 61, expands it internally, and exhausts it to the outside from an exhaust port 62. The type of expander 60 is not particularly limited, but may be a screw type. The expander 60 is mechanically connected to a generator 70.

The generator 70 generates electricity by being driven by the expander 60. The generator 70 is electrically connected to a power system (not shown) via wiring 5b. The electricity generated by the generator 70 is supplied to a destination via wiring 5b and the power system.

In this embodiment, the motor 30, the compressor 40, the expander 60, and the generator 70 are disposed on the upper part of the structure 10. Therefore, the motor 30, the compressor 40, the expander 60, and the generator 70 are disposed on the water 4.

The effects of the CAES power generation device 1 of this embodiment are explained below.

When the power generation facility 20 generates electricity using wind power, if there is a demand for electricity, it supplies the electricity to a supply destination (a grid, not shown). On the other hand, if there is no demand for electricity and electricity is to be stored, the generated electricity is supplied to the motor 30. When the compressor 40 is driven by the motor 30, compressed air is supplied from the compressor 40 to the pressure storage unit 50. As a result, water flows out from below the pressure storage unit 50, and the water level inside the pressure storage unit 50 drops. In addition, when compressed air is supplied from the pressure storage unit 50 to the expander 60, the expander 60 drives the generator 70. The electricity generated by the generator 70 is supplied to a supply destination, not shown. At this time, as the amount of compressed air in the pressure storage unit 50 decreases, water flows into the pressure storage unit 50 from below, and the water level inside the pressure storage unit 50 rises.

In this manner, in this embodiment, the water level inside the pressure accumulator 50 rises and falls as the amount of compressed air inside the pressure accumulator 50 increases or decreases. This automatically adjusts the volume required for the pressure accumulator 50, eliminating the need to prepare a large tank as the pressure accumulator 50.

In addition, since the pressure storage unit 50 is at least partially disposed underwater 3, the space underwater 3 can be utilized. Similarly, since the power generation equipment 20 that generates electricity using renewable energy is disposed on top of the structure 10 that floats on the water, the space above the water 4 can be utilized. Note that in this embodiment, the power generation equipment 20 generates electricity using wind power and is disposed on top of the structure 10, but depending on the power generation mode of the power generation equipment 20, it may not need to be exposed to the outside. In the case of a power generation equipment 20 that generates electricity in such a manner (for example, a mode that generates electricity using the temperature difference between day and night), it may be disposed inside the structure 10.

In addition, since the compressor 40, the pressure accumulator 50, and the expander 60, which need to be connected by the pipes 6a and 6b for flowing compressed air, are attached to the structure 10, the layout of the pipes 6a and 6b can be completed near the structure 10. In other words, there is no need to extend the pipes 6a and 6b from the floating structure 10 to the ground. The pipes 6a and 6b for flowing compressed air are thicker than the electric wires (wiring) 5a and 5b, and are not easy to handle, so the configuration of this embodiment is effective.

Second Embodiment
The CAES power generation device 1 of the second embodiment shown in Fig. 2 has a compressor/expander 80. Other configurations are substantially the same as those of the first embodiment. Therefore, the description of the parts shown in the first embodiment may be omitted. In Fig. 2, the structure 10 and the pressure accumulator 50 are shown in a cross-sectional view with hatching for clarity.

In this embodiment, the compressor 40 (see FIG. 1) and the expander 60 (see FIG. 1) in the first embodiment are integrated into a compressor/expander 80. The compressor/expander 80 may be a screw type. In addition, the motor 30 (see FIG. 1) and the generator 70 (see FIG. 1) in the first embodiment are integrated into a motor/generator 81.

According to this embodiment, the installation space for the compressor 40 (see FIG. 1) and the expander 60 (see FIG. 1) in the first embodiment can be reduced. In particular, the configuration of this embodiment is effective in the upper part of the structure 10, where the installation space is limited.

Third Embodiment
In the CAES power generation device 1 of the third embodiment shown in Fig. 3, the pressure accumulator 50 and the structure 10 are connected by a support member 11. Other configurations are substantially the same as those of the first embodiment. Therefore, the description of the parts shown in the first embodiment may be omitted. In Fig. 3, the pressure accumulator 50 is shown as a cross-sectional view with hatching for clarity.

In this embodiment, the pressure accumulator 50 is attached to the structure 10 via a support member 11. The pressure accumulator 50 is submerged in water 3 to a depth D. Here, the depth D indicates the distance from the water surface 2 to the upper surface inside the pressure accumulator 50. Since the water pressure increases as the depth D increases, the pressure of the compressed air stored in the pressure accumulator 50 can be increased by increasing the depth D.

The depth D can be changed depending on the compressor 40 and the expander 60. In general, the compressor 40 and the expander 60 are set to an operating pressure that improves the compression efficiency and expansion efficiency. Therefore, by setting the depth D according to the operating pressure, the compressor 40 and the expander 60 can achieve good compression efficiency and expansion efficiency. For example, when the pressure of the compressed air stored in the accumulator 50 is set to 4 to 7 Bar, the depth D can be set to 40 m or less.

According to this embodiment, by appropriately setting the depth D at which the pressure accumulator 50 is disposed, good compression efficiency and expansion efficiency can be achieved in the compressor 40 and the expander 60.

Fourth Embodiment
The CAES power generation device 1 of the fourth embodiment shown in Fig. 4 is different from the first embodiment in terms of the pressure accumulator 50 and the water current generator 70. Other configurations are substantially the same as those of the first embodiment. Therefore, the description of the parts shown in the first embodiment may be omitted.

In this embodiment, the pressure accumulator 50 is composed of tanks 51 to 54. The tanks 51 to 54 are disposed underwater 3 and are not exposed above the water 4.

A pipe 6c that is open to the water 3 is fluidly connected to the tanks 51 to 54. As the compressed air inside the tanks 51 to 54 increases or decreases, water flows in and out of the tanks 51 to 54 via the pipe 6c.

A water current generator 90 is provided in the pipe 6c. The water current generator 90 is driven by the water current that occurs as water flows in and out of the tanks 51-54, generating electricity. The water current generator 90 is electrically connected to a power system (not shown) via wiring 6c. The electricity generated by the water current generator 90 is supplied to the destination via wiring 5c and the power system. The structure of the water current generator 90 is not particularly limited, and a known structure can be used.

According to this embodiment, since electricity is generated not only by the generator 70 but also by the water current generator 90, a large amount of electricity can be generated. In addition, by appropriately setting the depth D to which the tanks 51 to 54 are submerged, as in the third embodiment, good compression efficiency and expansion efficiency can be achieved in the compressor 40 and the expander 60. In addition, since the pressure accumulator 50 consisting of the tanks 51 to 54 can be submerged in the water 3, construction is easy.

Fifth Embodiment
In the CAES power generation device 1 of the fifth embodiment shown in Fig. 5, a motor 30, a compressor 40, an expander 60, and a generator 70 are arranged in a structure 10. The configuration other than this is substantially the same as that of the first embodiment. Therefore, the description of the parts shown in the first embodiment may be omitted. In Fig. 5, the structure 10 and the pressure accumulator 50 are shown in a cross-sectional view with hatching for clarity.

In this embodiment, a storage space 7 is defined inside the structure 10. Water is prevented from entering the storage space 7. The storage space 7 contains a motor 30, a compressor 40, an expander 60, and a generator 70.

According to this embodiment, the motor 30, compressor 40, expander 60, and generator 70 can be protected from water. In addition, the power generation equipment 20 can be placed largely in the space above the structure 10.

Although specific embodiments of the present invention have been described above, the present invention is not limited to the above-described forms, and various modifications can be made within the scope of the present invention. For example, an appropriate combination of the contents of each embodiment may be one embodiment of the present invention.

1. Compressed air storage power generation equipment (CAES power generation equipment)
2 Water surface 3 Underwater 4 Above water 5a, 5b, 5c Wiring 6a, 6a, 6c Piping 7 Storage space 10 Floating body (structure)
11 Support member 20 Power generation equipment 30 Motor (electric motor)
40 Compressor 41 Intake port 42 Discharge port 50 Accumulator 51-54 Tank 60 Expander 61 Air supply port 62 Exhaust port 70 Generator 80 Compressor/expansion machine 81 Motor/generator machine 90 Water flow generator

Claims (3)

A floating body on the water,
A power generation facility that uses renewable energy to generate electricity;
an electric motor driven by the electric power generated by the power generation facility;
a compressor that compresses air by being driven by the electric motor;
a pressure accumulator that stores compressed air discharged from the compressor;
an expander that expands the compressed air stored in the pressure accumulator;
a generator driven by the expander,
The power generation facility is disposed on a structure that floats due to the buoyancy of the floating body,
the pressure accumulator unit is a plurality of tanks that are entirely disposed underwater, arranged in parallel with the compressor, and fluidly connected to the compressor through piping that is open underwater;
The piping is provided with a water flow generator that is driven by the water flow generated by the flow of water in and out of the piping, and generates electricity. The compressed air storage power generation system according to claim 1 , wherein the compressor and the expander are disposed on the structure. The compressed air storage power generation system according to claim 2 , wherein the compressor and the expander are integrally configured as a dual-purpose compressor/expander.

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